This proposal focuses on the oxygenation reactions carried out by the non-heme-iron-containing monooxygenase, the epoxidation/hydroxylation system of P. oleovorans. The significance of oxygenases--enzymes which catalyze the direct insertion of molecular oxygen into organic substrates--to biochemistry, medicine, and considerations of public health has by now been very well established. While P-450 and flavin-containing oxygenases have been intensively studied on a molecular level, the state of our understanding of non-heme iron monooxygenase catalysis is, by comparison, poor indeed. Thus, this project represents one of the very few efforts to define the molecular details of non-heme iron monooxygenase catalysis. Our work will involve mechanistic studies, the design and evaluation of novel substrate analogs, metal replacement and other active-site-directed chemical techniques and, finally, initial attempts to apply physical techniques to non-heme iron monooxygenases.